<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <script>
        /* match--返回匹配的值，是一个数组 
        replace()--替换
        */
        var str="hello";
        console.log(str.match('l'))    
        console.log(str.replace("l","g"))  //heglo
    </script>
</body>
</html>